The present invention is in the field of film laminates; more particularly, the invention relates to oriented film laminates of polyamides and ethylene vinyl alcohol copolymers.
Laminates containing at least one layer of ethylene vinyl alcohol copolymer and at least one polyamide, usually polyepsiloncaprolactam, layers of ethylene vinyl alcohol are disclosed in U.S. Pat. Nos. 3,595,740; 3,949,114; 4,254,169; and 4,284,674. The ethylene vinyl alcohol copolymer layer provides a barrier to oxygen permeability. Polyamides are used for physical property improvement, chemical resistance, and act as a barrier to gas permeability.
U.S. Pat. No. 4,294,935 discloses that a film of ethylene vinyl alcohol copolymer has improved gas barrier characteristics when expanded to an area from 4 to 20 times the original area.